Noncontact communication semiconductor device

ABSTRACT

A compact noncontact communication semiconductor device having a multidirectional or omnidirectional antenna and usable in a minuscule space to which the applications have conventionally been difficult is provided. The outer peripheral portion of a spherical IC  1  is covered with an insulating layer  4  having a thickness equal to or larger than the diameter of the IC  1 , and antenna patterns  2  are formed on the surface of the insulating layer  4 . The antenna patterns  2  can be configured either with a winding or by microprocessing using etching or laser beam, for example, for the conductive film formed on the surface of the insulating layer  4 . The antenna patterns  2  and the circuit pattern formed on the surface of the IC  1  are interconnected via a through hole  5.

This application is the national phase under 35 U.S.C. § 371 of PCTInternational Application No. PCT/JP99/05037 which has an Internationalfiling date of Sep. 16, 1999, which designated the United States ofAmerica.

TECHNICAL FIELD

The present invention relates to a noncontact communicationsemiconductor device comprising a radio communication antenna forhandling comparatively weak signals, in which power is received from areader-writer and signals are supplied to and received from thereader-writer by radio.

BACKGROUND ART

Conventionally, a semiconductor device comprising an IC chip mounted ona substrate formed in the shape of card, tag or coin is known. This typeof semiconductor device has a wealth of information amount and a highsecurity performance, and therefore has come to be widely used invarious fields including traffic, distribution and data communication.

Especially, a recently-developed noncontact communication semiconductordevice, in which the supply of power from a reader-writer to an IC chipand the transmission/reception of signals between a reader-writer and anIC chip are performed in a noncontact fashion using aradio-communication antenna without providing any external terminal onthe substrate, has the features that it is basically free of breakage ofthe external terminal unlike the contact, easy to store or otherwisehandle, and has a long service life and the maintenance of thereader-writer is easy. Another feature is that the data cannot be easilyaltered for an improved security performance, and therefore futureextension of the use thereof is expected in wider areas of application.

In the conventional noncontact communication semiconductor device, an ICchip with a flat circuit-forming surface, i.e. an IC chip in a thintabular form of silicon wafer with one side thereof is formed of arequired circuit pattern including arithmetic elements and storageelements. Also, a flat coil comprised of a winding coil of a conductoror a flat coil with a conductor film etched has been used as an antennafor radio communication. These antennas are generally mounted on asubstrate. In recent years, however, a flat coil directly formed as apattern on an IC chip or a coil wound around an IC chip as a core hasbeen proposed.

A thin tabular IC chip with a required circuit pattern integrated on oneside of a silicon wafer has a small bending strength. Therefore, adevice with an antenna mounted on an IC chip, to say nothing of a devicewith an antenna mounted on a substrate, cannot be used by itself as anoncontact communication semiconductor device, but an IC chip isrequired to be mounted on a substrate. Thus the conventional noncontactcommunication semiconductor device has the disadvantage that thestructure is complicated for an increased cost and the superficial shapebecomes bulky.

Also, the conventional noncontact communication semiconductor device, inwhich the substrate is formed in the shape of card, tag or coin and theantenna mounted on the device has a directivity between the front andback sides of the substrate, naturally has a limited field ofapplication. For example, the conventional noncontact communicationsemiconductor device cannot be placed and used in a fluid for measuringthe flow rate and flow velocity.

DISCLOSURE OF THE INVENTION

The present invention has been developed to obviate this problem of theprior art, and the object of the invention is to provide a noncontactcommunication semiconductor device which can be produced in small sizeat low cost and is applicable to fields to which the application hasthus far been difficult.

In order to solve the aforementioned problem, the present invention usesan IC having a three-dimensional circuit-forming surface and is soconfigured that an antenna for radio communication is formed as athree-dimensional pattern on the surface of the particular IC or anantenna for radio communication electrically connected to theinput/output terminal of a circuit three-dimensionally formed on thecircuit-forming surface is attached to the outer peripheral portion ofthe IC having the three-dimensional circuit-forming surface.

The aforementioned IC having a three-dimensional circuit-formingsurface, unlike the IC produced by the wafer process, is fabricated insuch a manner that required elements and wiring are formed using theprocess technique on the surface of a silicon base generated by aspecial method. Such an IC, in which the contour is configured with atleast two flat surfaces, is of two types. One has a contour containingat least two surfaces on which the circuits are formed. The other has acontour formed as a curved surface in the shape of sphere, grain, dish,hemoglobin, tetrapod, elongate or flat ellipsoid of revolution,tetrahedron enclosure, cubic, donuts, rice grain, gourd, seal or barrel,on which curved surface the circuits are formed.

In the noncontact communication semiconductor device described above, aninsulating layer may be formed as required between the IC and theantenna, and by adjusting the thickness of the insulating layer, thesize, i.e. the frequency characteristic of the antenna formed on thesurface of the insulating layer can be adjusted.

Of the two types of semiconductor devices described above, thesemiconductor device with a radio communication antenna attached to theouter peripheral portion of the IC having a three-dimensionalcircuit-forming surface may be such that the particular antenna isconfigured with either two conductive hollow hemispheric members withthe peripheral edge portions thereof arranged in opposed relation toeach other through a predetermined slit, or a conductive hollowspherical member having a slit in a portion thereof. These antennas havea superior high-frequency characteristic and therefore can secure a longcommunication distance in spite of their small size. Also, in the casewhere the required communication distance is short, an antenna formed ofa winding coil can be used.

In the case where the antenna described above is a winding coil or apattern formed by the microprocessing technique such as the laser beammachining or etching on the IC surface, an arbitrary antenna patternincluding the loop or dipole or a combination of the two can be used.Also, the antenna pattern is desirably multidirectional oromnidirectional, and formed to have a high sensitivity at least in threeor more specific directions.

An IC having a three-dimensional circuit-forming surface such as aspherical IC has a much higher bending strength (breaking strength) thana tabular IC chip. In the case where a radio communication antenna isformed as a pattern on the surface of such an IC or a radiocommunication antenna is attached to the outer peripheral portion of theIC, the substrate on which the antenna is to be mounted is not required.As compared with the conventional noncontact communication semiconductordevice requiring the substrate as an essential component part,therefore, the superficial shape thereof can be reduced in sizeremarkably, while at the same time making it possible to form amultidirectional or omnidirectional antenna having a high sensitivity inthree or more specific directions. Thus, a noncontact communicationsemiconductor device can be configured with only an IC and an antenna.This semiconductor device, being compact and in the shape of grain, canbe placed and used in a fluid, for example, for measuring the flow rateand the flow velocity. The application field of the noncontactcommunication semiconductor device of this type can thus be extended.Further, in view of the fact that the desired noncontact communicationsemiconductor device can be produced simply by forming a radiocommunication antenna as a pattern on the surface of the IC or byattaching a radio communication antenna to the outer peripheral portionof the IC, a noncontact communication semiconductor device can beproduced at lower cost than the noncontact communication semiconductordevice having a substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a noncontact communication semiconductordevice according to a first embodiment.

FIGS. 2A, 2B are sectional views of a conductor making up an antenna.

FIG. 3 is a schematic diagram for explaining an example of applicationof the noncontact communication semiconductor device and an example of aconfiguration of a reader-writer according to the first embodiment.

FIG. 4 is a perspective view of a noncontact communication semiconductordevice according to a second embodiment.

FIG. 5 is a perspective view of a noncontact communication semiconductordevice according to a third embodiment.

FIG. 6 is a perspective view of a noncontact communication semiconductordevice according to a fourth embodiment.

FIGS. 7A, 7B are perspective views of a noncontact communicationsemiconductor device according to a fifth embodiment.

FIG. 8 is a sectional view of a noncontact communication semiconductordevice according to a sixth embodiment.

FIG. 9 is a sectional view of a noncontact communication semiconductordevice according to a seventh embodiment.

FIG. 10 is a sectional view of a noncontact communication semiconductordevice according to an eighth embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION

A noncontact communication semiconductor device according to a firstembodiment of the present invention will be explained with reference toFIGS. 1 to 3. FIG. 1 is a perspective view of a noncontact communicationsemiconductor device according to a first embodiment, FIGS. 2A, 2B aresectional views of a conductor making up an antenna, and FIG. 3 is aschematic diagram for explaining an example of application of anoncontact communication semiconductor device and an example ofconfiguration of a reader-writer according to the first embodiment.

As apparent from FIG. 1, a noncontact communication semiconductor device11 according to this embodiment has an antenna pattern 2 formed on eachof the surface A and the surface A′ opposed to the surface A of athree-dimensionally formed IC 1, and the ends 3 of the antenna arearranged on the surface C orthogonal to the surfaces A and A′. Theantenna patterns 2 formed on the surfaces A and A′ are both wound in thesame direction with respect to a current i, so that when the current iis supplied to the antenna patterns 2, a magnetic field H in the samedirection normal to the surfaces A and A′ is generated from each antennapattern 2. Incidentally, although the antenna patterns 2 are each shownby a single line in the drawing, a predetermined number of turns can bewound in the form of coil.

The IC 1 formed in cube as described above, and at least two of the sixsurfaces making up the cube are formed with a required circuit pattern(not shown), and the portions of the surface C corresponding to theantenna ends 3 have an input/output port. This IC 1 is formed by formingrequired elements and wiring using the process technique on the surfaceof the cubic silicon base.

The antenna patterns 2 can be configured either by winding a conductoraround the IC 1, or by microprocessing, such as etching or applying alaser beam to the conductive film formed on the surface of the IC 1through an insulating layer (not shown). In the case where the antennapatterns 2 are formed of a conductor, the portion of the surface C ofthe IC 1 corresponding to the ends 3 of the antenna is formed with a padto which the ends of the antenna 2 are connected. Such a pad is notrequired in the case where the antenna patterns 2 are formed bymicroprocessing the conductive film.

In the case where the antenna patterns 2 are formed of a conductor, theconductor may be a wire member configured with a core wire 2 a of ametal material of a good conductor such as copper or aluminum coveredwith an insulating layer 2 b of resin or the like as shown in FIG. 2A,or a wire member configured with a core wire 2 a covered with a bondingmetal layer 2 c such as gold or solder which in turn is covered with aninsulating layer 2 b as shown in FIG. 2B. The diameter of the wiremember, though appropriately selectable as required, is most suitably 20μm to 100 μm in view of the need of preventing the breakage of thewinding and reducing the size of the antenna unit. Also, the antennapatterns 2 made of a conductor and the IC pad can be connected to eachother by a method such as wire bonding, soldering, ultrasonic fusion orconnection of an anisotropic conductor.

In the noncontact communication semiconductor device 11 according tothis embodiment, the radio communication antennas 2 are formed as apattern or a coil is wound on the surface of the cubic IC 1. Unlike inthe prior art, therefore, a substrate for mounting the antennas thereonis not required, so that the tabular form can be remarkably reduced insize as compared with the conventional noncontact communicationsemiconductor device comprising a substrate as an essential part. As aresult, a practical noncontact communication semiconductor device can beconfigured simply with the IC 1 and the antennas 2. This device is smalland granular, and therefore, as shown in FIG. 3, can be put into a fluid22 flowing in the tube 21 for allowing the reader-writer 23 to measurethe flow rate and the flow velocity thereof.

Specifically, the reader-writer 23 has a coil 24 adapted to beelectromagnetically coupled to the antennas 2 of the noncontactcommunication semiconductor device 11, which coil 24 is wound on theouter periphery of the tube member 21. With the reader-writer 23 havingthis configuration, the noncontact communication semiconductor device 11that has flowed in the tube member 21 together with the fluid 22approaches the coil 24, and is supplied with power from thereader-writer 23 when the antennas 2 of the noncontact communicationsemiconductor device 11 are electromagnetically coupled to the coil 24.Using this power, the noncontact communication semiconductor device 11performs the required arithmetic operation and transmits the requiredsignal to the reader-writer 23. The receiving level of the signal of thereader-writer 23 is varied with the relative positions of the antennas 2and the coil 24. By detecting the change of the receiving level by ahost computer connected to the reader-writer 23, therefore, the velocityand hence the flow rate of the fluid 22 flowing in the tube member 21can be determined by the arithmetic operation.

Further, the noncontact communication semiconductor device having theconfiguration described above can be obtained in the desired form simplyby forming patterns of a radio communication antenna or by winding awire coil on the surface of the IC, and therefore can be produced atlower cost than the noncontact communication semiconductor device havinga substrate.

A noncontact communication semiconductor device according to a secondembodiment of the invention will be explained with reference to FIG. 4.FIG. 4 is a perspective view of a noncontact communication semiconductordevice according to the second embodiment.

As apparent from FIG. 4, in a noncontact communication semiconductordevice 12 according to this embodiment, an antenna pattern 2 is formedon each of the surfaces A, A′ and surfaces B, B′ orthogonal to thesurfaces A, A′ of the IC 1 formed in cube, and the ends of the antennasare arranged on the surface C orthogonal to the surfaces A, A′ and thesurfaces B, B′. The antenna patterns 2 formed on the surfaces A and A′of the IC 1 are both wound in the same direction with respect to thecurrent i, so that when the current i is supplied to the antennapatterns 2, a magnetic field H1 is generated in the same directionnormal to the surfaces A and A′ from each antenna pattern 2. The antennapatterns 2 formed on the surfaces B and B′ are also wound in the samedirection with respect to the current i, so that when the current i issupplied to the antenna patterns 2, a magnetic field H2 is generated inthe same direction normal to the surfaces B and B′ from each antennapattern 2. The other functions are the same as those of the noncontactcommunication semiconductor device 11 according to the first embodimentand will not be described to avoid duplication.

The noncontact communication semiconductor device 12 according to thisembodiment exhibits the same effect as the noncontact communicationsemiconductor device 11 according to the first embodiment, and theantenna patterns 2 are formed on the surfaces A, A′ and the surfaces B,B′ of the IC 1. Therefore, there can be obtained a noncontactcommunication semiconductor device equipped with a multidirectionalantenna unit having a high sensitivity in two directions perpendicularto the surfaces A, A′ and the surfaces B, B′.

A noncontact communication semiconductor device according to a thirdembodiment of the present invention will be explained with reference toFIG. 5. FIG. 5 is a perspective view of a noncontact communicationsemiconductor device according to the third embodiment.

As apparent from FIG. 5, the noncontact communication semiconductordevice according to the third embodiment 13 has antenna patterns 2formed on the surfaces A, A′, the surfaces B, B′ and the surfaces C, C′of the IC 1 formed in cube, and the ends 3 of the antennas are arrangedon the surface C. The antenna patterns 2 formed on the surfaces A, A′ ofthe IC 1 are both wound in the same direction with respect to thecurrent i, so that when the current i is supplied to the antennapatterns 2, a magnetic field Hi is generated in the same directionnormal to the surfaces A, A′ from each antenna pattern 2. The antennapatterns 2 formed on the surfaces B, B′ are also wound in the samedirection with respect to the current i, so that when the current i issupplied to the antenna patterns 2, a magnetic field H2 is generated inthe same direction normal to the surfaces B, B′ from each antennapattern 2. Further the antenna patterns 2 formed on the surfaces C, C′are also wound in the same direction with respect to the current i, sothat when the current i is supplied to the antenna patterns 2, amagnetic field H3 is generated in the same direction normal to thesurfaces C, C′ from each antenna pattern 2. The other functions are thesame as those of the noncontact communication semiconductor device 11according to the first embodiment and will not be described to avoidduplication.

The noncontact communication semiconductor device 13 according to thisembodiment exhibits the same effect as the noncontact communicationsemiconductor device 11 according to the first embodiment, and theantenna patterns 2 are formed on the surfaces A, A′, the surfaces B, B′and the surfaces C, C′ of the IC 1. Therefore, there can be obtained anoncontact communication semiconductor device equipped with amultidirectional antenna unite having a high sensitivity in threedirections perpendicular to the surfaces A, A′, the surfaces B, B′ andthe surfaces C, C′.

A noncontact communication semiconductor device according to a fourthembodiment of the present invention will be explained with reference toFIG. 6. FIG. 6 is a perspective view of a noncontact communicationsemiconductor device according to the fourth embodiment.

As apparent from FIG. 6, the noncontact communication semiconductordevice 14 according to this embodiment is characterized in that antennapatterns 2 are continuously formed in three directions on the peripheralsurfaces of the IC 1 formed in cube, and the ends 3 of the antennas arearranged on a given one of the surfaces, or the surface C in the showncase. The antenna patterns 2 can be formed by winding a conductor asillustrated in FIG. 2. In the noncontact communication semiconductordevice 14 according to this embodiment, when a current i is supplied tothe antenna patterns 2, three magnetic fields H1, H2 and H3 orthogonalto each other are generated in three directions from the coils wound onthe respective peripheral surfaces of the IC 1. The other functions arethe same as those of the noncontact communication semiconductor device11 according to the first embodiment and will not be described to avoidduplication.

The noncontact communication semiconductor device 14 according to thisembodiment exhibits a similar effect to the noncontact communicationsemiconductor device 13 according to the third embodiment.

A noncontact communication semiconductor device according to a fifthembodiment of the invention will be explained with reference to FIGS.7A, 7B. FIGS. 7A, 7B are perspective views of a noncontact communicationsemiconductor device according to the fifth embodiment.

As apparent from FIGS. 7A, 7B, the noncontact communicationsemiconductor device 15 according to this embodiment is characterized inthat an IC having a spherical contour is used as an IC 1 and an antennapattern 2 is formed on the surface of the IC 1. The antenna pattern 2can be configured with a winding or by microprocessing using etching orlaser beam for the conductive film formed on the surface of the IC 1through an insulating layer (not shown). FIG. 7A is an example in whichthe antenna 2 is formed along the surface of the IC 1 in the shape ofthe seam of a baseball, and FIG. 7B an example in which a plurality ofspiral coils are distributed over the surface of the IC 1. In eithercase, there can be obtained a noncontact communication semiconductordevice including a multidirectional antenna having a high sensitivity intwo or more multiple directions. The other functions are the same asthose of the noncontact communication semiconductor device 11 accordingto the first embodiment and therefore will not be described to avoidduplication.

The noncontact communication semiconductor device 15 according to thisembodiment also exhibits a similar effect to the noncontactcommunication semiconductor devices 11, 12, 13, 14 according to thefirst to fourth embodiments, respectively.

A noncontact communication semiconductor device according to a sixthembodiment of the invention will be explained with reference to FIG. 8.FIG. 8 is a sectional view of a noncontact communication semiconductordevice according to the sixth embodiment.

As apparent from FIG. 8, the noncontact communication semiconductordevice 16 according to this embodiment is characterized in that theouter peripheral portion of a spherical IC 1 is covered with aninsulating layer 4 having a thickness equal to or larger than thediameter of the IC 1, and an antenna pattern 2 is formed on the surfaceof the insulating layer 4. The antenna pattern 2 may be eitherconfigured of a winding or configured by microprocessing such asmachining by etching or a laser beam for the conductive film formed onthe surface of the insulating layer 4. The antenna pattern 2 isconnected via through holes 5 to input/output ports 9 a of the circuitpattern 9 formed on the surface of the IC 1. The other functions are thesame as those of the noncontact communication semiconductor device 11according to the first embodiment and therefore will not be described toavoid duplication.

In the noncontact communication semiconductor device 16 according tothis embodiment, which has a similar effect to the noncontactcommunication semiconductor device 15 according to the fifth embodiment,the outer peripheral surface of the spherical IC 1 is covered with theinsulating layer 4 having a thickness equal to or larger than thediameter of the IC 1 and an antenna pattern 2 is formed on the surfaceof the insulating layer 4. Therefore, the size of the antenna pattern 2can be increased as compared with the case in which the antenna pattern2 is formed on or in the neighborhood of the surface of the IC 1,thereby making it provide a noncontact communication semiconductordevice having an antenna superior in high-frequency characteristic.

A noncontact communication semiconductor device according to a seventhembodiment of the invention will be explained with reference to FIG. 9.FIG. 9 is a sectional view of a noncontact communication semiconductordevice according to the seventh embodiment.

As apparent from FIG. 9, the noncontact communication semiconductordevice 17 according to this embodiment is characterized in that theouter peripheral portion of a spherical IC 1 is covered with aninsulating layer 4 having a thickness equal to or larger than thediameter of the IC 1, and an antenna 2 including two conductive hollowhemispherical members 2 a, 2 b is deposited on the outer surface of theinsulating layer 4. A predetermined gap 6 is formed between the opposedperipheral edge portions of the two conductive hollow hemisphericalmembers 2 a, 2 b. Each of the conductive hollow hemispherical members 2a, 2 b is connected via through holes 5 to the circuit pattern formed onthe surface of the IC 1. The other functions are the same as those ofthe noncontact communication semiconductor device 16 according to thesixth embodiment and therefore will not be described to avoidduplication.

The noncontact communication semiconductor device 17 according to thisembodiment, which has a similar effect to the noncontact communicationsemiconductor device 16 according to the sixth embodiment, uses theantenna 2 configured with the two conductive hollow hemisphericalmembers 2 a, 2 b, and therefore can provide a noncontact communicationsemiconductor device equipped with an antenna having a superiorhigh-frequency characteristic as compared with the case of using anantenna formed as a pattern or an antenna configured with a winding.

A noncontact communication semiconductor device according to an eighthembodiment of the invention will be explained with reference to FIG. 10.FIG. 10 is a sectional view of a noncontact communication semiconductordevice according to the eighth embodiment.

As apparent from FIG. 10, the noncontact communication semiconductordevice 18 according to this embodiment is characterized in that aconductive hollow spherical member having a slit 8 in a portion thereofis used as an antenna 2, a spherical IC 1 is contained in the antenna 2,and two points on the inner surface of the antenna 2 are connected byconductors 7 to the circuit pattern formed on the surface of the IC 1.The other functions are the same as those of the noncontactcommunication semiconductor device 16 according to the sixth embodimentand therefore will not be described to avoid duplication.

The noncontact communication semiconductor device 18 according to thisembodiment also has a similar effect to the noncontact communicationsemiconductor device 17 according to the seventh embodiment.

Although a cubic IC 1 or a spherical IC 1 is used in the embodimentsdescribed above, the invention is not limited to such shapes of the IC1, but can use an IC having a three-dimensional circuit-forming surfacewith any arbitrary contour in the shape of grain, dish, hemoglobin,tetrapod, elongate ellipsoid of revolution, tetrahedron enclosure,donuts, rice grain, gourd, seal or barrel.

INDUSTRIAL APPLICABILITY

As described above, in a noncontact communication semiconductor deviceaccording to this invention, using an IC having a three-dimensionalcircuit-forming surface, a radio communication antenna is formed as apattern on the surface of an IC or a radio communication antennaelectrically connected with the input/output terminals of the circuitformed on the circuit-forming surface of the IC is attached on the outerperipheral portion of the IC. Therefore, the superficial shape of thenoncontact communication semiconductor device can be remarkably reducedin size without the substrate for mounting the antenna thereon ascompared with the conventional noncontact communication semiconductordevice having a substrate as an essential component part, while at thesame time making it possible to form a multidirectional antenna or anomnidirectional antenna having a high sensitivity in three or moremultiple directions. As a result, a practical noncontact communicationsemiconductor device can be configured with only an IC and an antenna.At the same time, being compact and in the shape of grain, applicationsto the fields in which the conventional noncontact communicationsemiconductor device is difficult to use such as measurement of the flowrate and flow velocity within a fluid are made possible. Also, theabsence of a substrate simplifies the structure and makes possibleproduction at a lower cost than the conventional noncontactcommunication semiconductor device having a substrate.

What is claimed is:
 1. A noncontact communication semiconductor devicecharacterized by comprising an IC having a three-dimensionalcircuit-forming surface and a radio communication antenna formed as athree-dimensional pattern on the surface of said IC.
 2. A noncontactcommunication semiconductor device as described in claim 1,characterized in that said IC has a curved contour surface.
 3. Anoncontact communication semiconductor device as described in claim 2,characterized in that said IC is spherical.
 4. A noncontactcommunication semiconductor device as described in claim 1,characterized in that an insulating layer is interposed between said ICand said antenna.
 5. A noncontact communication semiconductor devicecharacterized by comprising an IC having a three-dimensionalcircuit-forming surface and a radio communication antenna attached onthe outer peripheral surface of said IC and electrically connected tothe input/output terminals of the circuit formed three-dimensionally onsaid circuit-forming surface, wherein said antenna is configured withtwo conductive hollow hemispherical members, and the peripheral edgeportions of these two conductive hollow hemispherical members arearranged in opposed relation to each other through a predetermined slit.6. A noncontact communication semiconductor device characterized bycomprising an IC having a three-dimensional circuit-forming surface anda radio communication antenna attached on the outer peripheral surfaceof said IC and electrically connected to the input/output terminals ofthe circuit formed three-dimensionally on said circuit-forming surface,wherein said antenna is configured with a conductive hollow sphericalmember having a slit in a portion thereof.